FLAT METHOD
Original amount × rate × time
The same original principal is used throughout.
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Flat vs Reducing Interest Rate Calculator
Is an 8% flat loan cheaper than a 14% reducing loan? Convert a flat rate to its equivalent reducing rate, compare two offers and see how upfront charges change the cost.
No loginMonthly schedule & CSVFees shown separately
Enter your two loan offers
Keep the amount and term identical. The rates below are examples, not lender offers.
YOUR MONTHLY COMPARISON
Offer A · Flat
—
Estimated monthly EMI
Offer B · Reducing
—
Estimated monthly EMI
Flat rate → equivalent reducing rate—Nominal annual rate, monthly reducing basis, excluding fees.
Annualised monthly cashflow rate
With your upfront charges: A — · B —
12 × the monthly rate matching net proceeds and EMIs. This illustration may differ from the lender’s disclosed APR; see the method below.
Where does your money go?
The principal is the same, but interest, charges and cash received can differ. Edit either fee to see the effect.
| Amount over the full term | Offer A · Flat | Offer B · Reducing |
|---|
Repayments + charges is the gross cash outflow. Interest + charges is the cost above principal. Do not add the charges again to either total.
View the full monthly repayment schedule
Flat repayments are shown as cash payments only. The reducing offer includes interest, principal and closing balance. The lender’s allocation on a flat-rate contract can differ.
| Month | A · payment | B · payment | B · interest | B · principal | B · balance |
|---|
What is the difference between flat and reducing interest?
Flat interest uses the original loan amount for the whole term. A flat 8% on ₹5 lakh for three years means ₹40,000 interest each year, or ₹1,20,000 altogether. Repaying some principal each month does not reduce that flat interest calculation.
Reducing interest uses the outstanding principal. Each monthly EMI pays that month’s interest and reduces principal. The next month’s interest is calculated on the smaller balance. With a constant rate, the EMI stays level while its interest and principal components change.
REDUCING METHOD
Opening balance × monthly rate
The interest base falls as principal is repaid.
Is 8% flat cheaper than 14% reducing?
For this ₹5 lakh, 36-month example, the 14% reducing offer has a slightly lower EMI and interest cost. A smaller printed percentage does not settle the comparison. These are original mathematical illustrations, with equal ₹5,000 upfront charges for both offers.
| 36-month example | 8% flat | 14% reducing |
|---|---|---|
| Monthly EMI | ₹17,222.22 | ₹17,088.81 |
| Total interest | ₹1,20,000.00 | ₹1,15,197.34 |
| Interest + ₹5,000 charges | ₹1,25,000.00 | ₹1,20,197.34 |
The 8% flat rate is equivalent to about 14.55% nominal annual reducing interest before fees for this payment pattern. That is a conversion of equal cashflows, not a claim that all 8% flat loans have the same equivalent rate. Change the term above and the conversion changes.
How do I convert a flat rate to a reducing rate?
First calculate the flat EMI. Then find the monthly reducing rate that gives that same EMI for the same amount and number of payments. This tool solves the equation numerically; it does not multiply every flat rate by a fixed factor.
Flat interest = P × f × n ÷ 1200
Flat EMI = (P + flat interest) ÷ n
Reducing EMI = P × r ÷ [1 − (1 + r)−n]
Here P is principal in rupees, f is the flat annual percentage, n is months, and r is the reducing monthly rate (annual percentage ÷ 1200). At a zero reducing rate, EMI is P ÷ n. The equivalent nominal annual reducing percentage is the solved monthly rate × 1200.
Why do processing fees change the comparison?
A ₹5 lakh loan with ₹5,000 deducted at the start provides ₹4,95,000 net cash, even though repayments are based on ₹5 lakh. Paying that fee separately at the same starting time has the same net cash effect in this simplified model. The fee does not change the modeled EMI, but it increases the cost of accessing the money.
For the rate including charges, the calculator solves P − upfront charges = sum of each EMI discounted at the monthly cashflow rate, then multiplies that monthly rate by 12. This is a nominal annualised measure; it is not an effective annual compounded rate. It is not a substitute for a lender’s Key Facts Statement (KFS), disclosed APR or dated repayment schedule. Their fee inclusions, dates and calculation conventions can differ.
Simple Hindi explanation
Flat rate mein poore loan amount par interest calculate hota hai, chahe aap har mahine principal chuka rahe hon. Reducing rate mein bache hue principal par interest lagta hai. Isliye sirf “8%” aur “14%” dekhkar loan compare na karein—same amount, same months, EMI aur fees ka total dekhein.
Questions to ask before accepting a loan
- Is the quoted rate flat, monthly reducing or calculated another way?
- How much will I actually receive after all upfront deductions?
- What are the EMI dates, number of instalments and total charges?
- Are insurance, prepayment charges, late fees or a final balloon payment involved?
- Does the written schedule match the offer explained to me?
If both offers use reducing interest and you want to compare a home-loan balance transfer, use the home loan comparison calculator. To model regular extra principal payments, use the EMI calculator with extra payments.
Calculation assumptions and limits
The model uses equal monthly periods, a fixed rate, a single disbursement at time zero and the first payment one month later. It includes only the upfront charges you enter. It excludes broken-period interest, irregular dates, financed fees, floating-rate resets, missed payments, prepayments, late charges and balloon payments. EMI calculations keep full precision internally; display and CSV amounts round to two decimals. The last reducing payment clears any numerical residue.
Supported inputs: ₹1 to ₹100 crore, 1–360 whole months and annual rates from 0% to 60%. Enter charges below principal so net proceeds stay positive. Very high fee-to-loan ratios can produce unusually large annualised rates; that is a cashflow effect, not a recommended borrowing scenario. The tool does not assess loan eligibility or recommend a lender.
Frequently asked questions
Is flat interest the same as a fixed interest rate?
No. Flat describes the amount used to calculate interest. Fixed describes whether a rate can change. A fixed-rate loan can still calculate interest on a reducing balance.
Is reducing interest always cheaper?
At the same positive numeric annual rate, principal and term, this monthly reducing model produces less interest than the flat model when there is more than one payment. Real offers can have different rates and fees. Compare their cashflows rather than assuming one label is always cheaper.
What is 10% flat in reducing interest?
There is no single answer without a tenure and payment pattern. Enter 10% as the flat rate and your number of months above. The equivalent rate excludes fees; the separate cashflow rate includes the upfront charges you enter.
Can I use this for a car, bike or personal loan?
Yes, if the offer matches the fixed-rate monthly repayment assumptions. Use the loan principal, not the vehicle’s full price including a down payment. Ask for the written schedule if the lender uses advance EMIs, a balloon amount or different payment dates.
Why does a one-month loan give the same interest at the same rate?
With only one payment, no earlier repayment has reduced the balance. Both methods charge one month of interest on the original amount in this model. Fees can still make their overall costs different.
Does a zero-interest loan have no cost?
Only if there are no other relevant charges. A zero-rate offer with upfront charges has a positive borrowing cost in this model. Check all written terms.
Sources and method
Definitions cross-checked with ICICI Bank’s explanation of flat and reducing loan interest and HDFC Bank’s flat-interest calculator guide. The examples, fee comparison and cashflow solver on this page are our own illustrations. Method checked 22 October 2026.
Educational estimates. Verify the final loan terms with your lender. Calculator inputs are processed in your browser and are not submitted by this tool.